The long range goal of this program is to develop for commercial purposes and then market a movable platform system for the diagnostic screening and treatment evaluation of patients with vestibular equilibrium disorders and vertigo. During Phase I a concept for testing which evolved over ll years of NIH sponsored research will be realized by designing a movable platform structure and hydraulic power system appropriate for clinical uses. The movable platform system will be made lightweight, compact, easy to operate and service, safe, and as cost-effective as possible. Future plans call for fabrication and placement of prototype systems in selected clinical environments. Performance of the prototype equipment and methods for presentation of results to the clinician will be evaluated before full scale commercial production.